In the prior art, various clamps and vises are used to rigidly retain one or more workpieces on which work is to be performed.
For example, a wood vise may be used to hold several workpieces together in a gluing operation. One such vise consists of a fixed jaw, a movable jaw, and a longitudial bar or rod therebetween. A threaded rod is carried by the fixed jaw, and the rod has an abutment for engaging a side edge of the workpiece(s). The opposite side edge of the workpiece(s) engage a corresponding abutment on the movable jaw. The rod is actuated by a suitable crank carried by the fixed vise jaw.
When using this type of vise, the workpiece(s) may inadvertently contact the vise bar and become scratched or otherwise marred. This problem is especially aggravating to the craftsman, since hobbycraft woods or other expensive materials are frequently used.
Moreover, when several workpieces are alined with one another and are positioned within the vise, and when the threaded rod is tightened to rigidly retain the workpieces, the continued pressure of the threaded rod under actuation by the crank causes the workpieces to "bow" somewhat, so that the finished article will not be completely planar or "true". This situation becomes more pronounced when the workpieces are relatively thin or are relatively soft. Besides, it is difficult to control the degree of clamping pressure.